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V. B. RYERSON.

rizing Or'es.

Patented Aug. 14, 1866.

Desulphu N. PETERS. Phcko-Lflhogmphnr. Washingtun. D. c

UNITED STATES PATENT OFFICE,

VAN BUREN RYERSON, OF NEW YORK, N. Y.

IMPROVEMENT IN DESULPHURIZING ORES.

Specification forming part of Letters Patent No. 57,194, dated August 14, 1866.

To all whom it may concern:

Be it known that I, VAN BUREN RYERsoN, of the c'ty, county, and State of New York, have invented a new and useful Process for Desulphurizing Ores; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, making part of this specification, in which- Figure 1 is a plan of an apparatus suitable for working the said process; Fig. 2, a longitudinal vertical section taken at the line A a of Fig. 1; Fig. 3, a crossvertical section taken at the line B b of Fig. 2; Fig. 4, a section, on an enlarged scale, of one of the blowers, taken at thelineG c of Fig. 1; Fig. 5, a section taken at the line D d of Fig. 4; Fig. 6, a vertical section taken at the line E e of Fig.1, and Fig. 7 a horizontal section taken at the line Ff of Fig. 6. v

The same letters indicate like parts in all the figures.

The leading object of my said invention is to desulphurize the sulphurets of the base metals which contain and envelop particles of the precious metals, and which, until decomposed,pre\-'ent the particles of the precious metals from being taken up by mercury in the well-known amalgamating process; but my said process can be applied to decompose or desulphurize the sulphurets or ores containing sulphurets, whether to obtain precious metals or for any other purpose.

The ore to be treated is charged in muffles or retorts a, through doors 0, the said muftles being heated by the passage of the products of combustion from the fire-chamber c of a furnace, passing through a flue-space under and over them on the way to the chimney-stack (1. Four such muffles are represented; but the number may be varied from one upward.

Atmospheric air is admitted to themuftles, and when the ore is thus submitted to heat in the presence of air sulphurous gas will be produced and pass from the muffles through apertures c at the back into a side chamber, f, and into this chamber, and near to each aperture c, I place a vessel with nitrate of soda or potash, covered with a cloth wet or saturated With-sulphuric acid, to give out binoXide of nitrogen, which mingles in the chamber with the sulphurous gas from the ore..

Any other equivalent means for producing the nitrous-acid gas may be substituted. By this treatment a portion of the oxygen of the atmospheric air will unite with the sulphur of the ore and produce sulphurous-acid gas, while the base metals of the ore will be oxidized.

At the beginning of the process above described a charge of the ore which has been previously desulphurized and its Base metals oxidized, as above described, is charged in a series of receivers, g, each of which surrounds a tubular pipe, it, that communicates by pipes t'wit-h the cases j of rotating blowers k, and the sides of the cases are, in turn, connected by pipes l lwith the side chamber, f. I prefer to use two such blowers for four muftles and four receivers, g. The tubular pipes h are pierced with uum erous fine holes for the escape of gases into the charges of ores in thereceivers g, and in the center of each of the said receivers there is a central pipe, m, which communicates with a steam-boiler, and, by preference, with the superheater of a steam-boiler, for the introduction of superheated steam, which will escape in fine jets into the charges of desulphurized ores in the said receivers g.

The sulphurous gas from the muffles will mingle in the side chamber,f, with the binoxide of nitrogen gas produced in the said chamber, and with the atmospheric air, and, so mingled, will be drawn from the side chamber by the suction of the blowers, and thence forced through the pipes i and perforations in the tubular pipes it into the charges of desulphurized ore in the receivers at the same time that steam is discharged in numerous finejets.

The effect of the mingled gases and steam is to change the sulphurous gas into sulphuric acid and the oxides of the base metals into sulphates or sulphides. If gold be contained in the ore which has been thus treated it will be entirely freed from the coatings of the sulphurets or oxides of the base metals, and, however fine the particles of it may be, they can be taken up by the usual process of amalgamation; but if the ore contains silver it (the silver) will be converted into a sulphate or sulphide, and can be precipitated from the solution by the usual process.

Having thus described my said process, and the apparatus which I prefer to use for the working of the said process, 1 wish it to be distinctly understood that I do not limit my claim to the use of such apparatus, as other suitable apparatus may be substituted for the working of my invention.

What I claim as new, and desire to secure by Letters Patent, is V The process, substantially as described, of

subjecting ores which have been desulphurized and their base metals oxidized to the action of the gases evolved from the process of desulphurizing another charge of such ore's in the presence of atmospheric air, and mingled with binoxidc of nitrogen and jets of steam, for the purpose specified.

V. B. RYERSON. Witnesses:

ANDREW DE LACY, WM. H. BISHOP. 

